The present invention relates to powdered compositions and methods for absorbing, deodorizing and removing liquid wastes, and more particularly to inorganic salt compositions that form cohesive solid matrices upon absorption of liquids, thereby facilitating removal of liquid wastes from underlying surfaces.
A variety of chemical compositions are known for cleaning and deodorizing carpets, curtains, and other textiles, existing in both liquid and powdered forms. Such formulations are generally effective in removing stains and malodors associated with such things as pet urine and other moisture-related stains and spills. Often the compositions are powdered formulations containing components such as inorganic salts and zeolites.
For example, Corey et al. (U.S. Pat. No. 4,304,675) disclose a powdered composition and method for deodorizing rugs comprising 50-98 wt. % of an inorganic salt (i.e. sodium or calcium sulfates, bicarbonates, chlorides, and mixtures thereof), 0.5-30 wt. % of natural or synthetic zeolites which act as anti-static and Theological control agents, up to 20 wt. % of a liquid agglomerating agent, and 0.5-5 wt. % fragrance. The powder is applied to the rugs by shaking from a container and removed with a vacuum cleaner. However, the composition of Corey et al. is useful only for deodorizing carpets and imparting other attributes such as antistatic and anti-soiling effects to the surface, but the composition does not satisfactorily absorb or remove spilled liquids from the carpet.
Dunson, Jr. (U.S. Pat. No. 5,137,687) discloses an odor treatment method which works by reacting odors emitted from systems such as sewage treatment facilities with core particles containing silica and inorganic carrier salts such as sulfates, chlorides, and bicarbonates. However, the odor treatment of Dunson, Jr. merely curbs odors on an industrial scale and cannot be used for moisture absorption to contain a spill.
Colurciello et al. (U.S. Pat. No. 5,736,494) teach a flowable granular carpet cleaning composition comprising 25-40 wt. % cellulose, 0-7 wt. % zeolite or silica gel, 12-20 wt. % of an inorganic salt, 0.1-10 wt. % solvent, 0-5 wt. % acid, and minor amounts of surfactants. The inorganic salt is selected from sodium carbonate, sodium bicarbonate, and sodium sesquicarbonate. The wet formulation is applied to carpeting or other textiles, rubbed into the stained area, then permitted to dry until the composition combines with the dirt to form dry residues. The dry residues can then be removed by vacuuming or brushing.
Smith (U.S. Pat. No. 4,566,980) teaches a powdered composition for removing spills from carpeting. The powder contains inorganic salts, such as sodium sulfate and sodium bicarbonate, and an agglomerating agent. Upon saturation with water, the inorganic salt particles xe2x80x9cwet outxe2x80x9d but maintain their particulate structural integrity. The absorbed liquid does not cause the particles to stick together or adhere to each other or the carpet. Because the spent particles do not clump to form a cohesive mass, they are easily removed from the carpet by vacuuming.
Weller (U.S. Pat. No. 4,873,000) teaches a formulation for freshening and deodorizing carpets which incorporates inorganic salts, such as chlorides, bicarbonates, and sulfates, aluminum silicate clay, a liquid agglomerating agent, and a fragrance. After sprinkling the powdered composition onto carpeting, the spent cleaning particles are easily removed by vacuuming.
It is apparent from the prior art that powdered inorganic salt systems exist that are useful in cleaning and deodorizing textile surfaces or for removing odors from the air. However, until now, there were no known inorganic salt powders effective in absorbing and containing liquid spills on smooth, hard surfaces, as well as on fibrous, irregular materials. Nor were any of the existing compositions useful in absorbing both water-based and oil-based stains and spills. A need therefore exists for powdered compositions that are effective in absorbing and removing a variety of stains and spills from a variety of surfaces. For example, inorganic powdered compositions that can effectively remove not only household-related aqueous spills, such as pet urine, but also spilled fuel oil and liquid biohazardous waste materials would be advantageous. It would also be advantageous if such formulations were environmentally safe and nonreactive with the underlying surfaces, and if the spilled materials could be removed easily, preferably without vacuuming, and disposed of safely. The novel powdered compositions of the present invention and the inventive methods for removing liquid wastes disclosed herein satisfy the aforementioned needs.
The present invention is based on the unexpected discovery that powdered compositions containing specific inorganic salt materials in admixture with silica gel in specific limited proportions relative to each other and to other components can effectively clean, deodorize, and absorb liquid wastes from both irregular fibrous surfaces, such as carpets, and smooth hard surfaces, such as floors. Surprisingly, unlike prior art compositions containing zeolites or silica gel, when the powdered compositions come in contact with liquid wastes, the absorbent properties contain the spill, creating a cohesive solid matrix that allows for easy and safe disposal. The novel compositions are effective in removing the moisture and malodors associated with pet urine and other moisture-related stains, and in absorbing biohazards, such as blood, vomit, and urine. In addition, the mixtures of the present invention can be utilized for the absorption of fuel oils and hydrocarbons. Furthermore, the novel powdered compositions do not impart undesirable properties on the cleaned surfaces and are environmentally safe.
Another advantage of the present compositions, which makes them more desirable for use than prior art formulations, is that the present powders can buffer both acids and bases. Thus, spills that are acidic or caustic may be safely disposed following treatment with the present compositions. In addition, the present compositions can lower the flash point of most solvents.
Therefore, in one aspect, the invention is a powdered composition useful in absorbing and deodorizing liquid waste. The composition comprises in admixture:
(a) from about 5 parts by weight to about 85 parts by weight of an alkali metal sulfate;
(b) from about 1 part by weight to about 45 parts by weight silica gel;
(c) from about 1 part by weight to about 75 parts by weight of an alkali metal bicarbonate;
(d) from about 1 part by weight to about 70 parts by weight of an alkaline earth metal sulfate; and
(e) from about 0 parts by weight to about 2 parts by weight fragrance additive.
A cohesive solid matrix is formed when the powdered composition contacts the liquid waste.
In another aspect, the composition comprises in admixture:
(a) from about 20 parts by weight to about 85 parts by weight of an alkali metal sulfate;
(b) from about 5 parts by weight to about 45 parts by weight silica gel;
(c) from about 1 part by weight to about 45 parts by weight of an alkali metal bicarbonate;
(d) from about 1 part by weight to about 15 parts by weight of an alkaline earth metal sulfate; and
(e) from about 0 parts by weight to about 2 parts by weight fragrance additive.
A cohesive solid matrix is formed when the powdered composition comes into contact with the liquid waste.
As used herein, the term xe2x80x9cparts by weightxe2x80x9d indicates the weight of the corresponding ingredient in the powdered compositions based on the total weight of the powdered compositions. The term xe2x80x9cwt. %xe2x80x9d indicates the percentage by weight of the corresponding ingredient in the compositions based on the total active ingredient weight of the powdered compositions.
Preferably, in the novel materials disclosed herein, the alkali metal sulfate is sodium sulfate, the alkali metal bicarbonate is sodium bicarbonate, and/or the alkaline earth metal sulfate is calcium sulfate.
In another aspect, the invention is a process for removing liquid waste comprising: (a) applying a powdered composition, as set forth above, to a liquid waste residing on a surface; (b) allowing the liquid waste and powdered composition to form a cohesive solid matrix; and (c) removing the cohesive solid matrix from the surface. Illustrative liquid wastes includes fuel oils, hydrocarbons, urine, and other oil-based and water-based spills.
The compositions optionally comprise from about 0.01 parts by weight to about 5 parts by weight of an alkali or alkaline earth metal halogen compound, such as sodium hypochlorite or calcium hypochlorite. This halogen component is particularly desirable for disinfecting biohazardous liquid wastes.
In another aspect, the invention is a process for removing liquid biohazards which comprises: (a) applying the aforementioned halogen-containing powdered composition to a liquid biohazard residing on a surface; b) allowing the liquid biohazard and powdered composition to form a cohesive solid matrix; and (c) removing the cohesive solid matrix from the surface.
In a preferred embodiment, the powdered composition comprises (a) from about 70 parts by weight to about 85 parts by weight of sodium sulfate; (b) from about 5 parts by weight to about 20 parts by weight silica gel; (c) from about 1 part by weight to about 25 parts by weight of sodium bicarbonate; (d) from about 1 part by weight to about 15 parts by weight of calcium sulfate; and (e) from about 0 parts by weight to about 2 parts by weight of the fragrance additive. More preferably, the powdered composition comprises (a) about 74 parts by weight of sodium sulfate; (b) about 12 parts by weight silica gel; (c) about 11 parts by weight of sodium bicarbonate; and (d) about 3 parts by weight of calcium sulfate. Another more preferred embodiment comprises (a) about 75 parts by weight of sodium sulfate; (b) about 15 parts by weight silica gel; (c) about 5 parts by weight of sodium bicarbonate; and (d) about 5 parts by weight of calcium sulfate.
To restate, the present invention relates to novel powdered compositions useful in cleaning, deodorizing, and removing liquid wastes, such as biohazards, moisture-related stains, oil-based spills, and hydrocarbons, from a variety of surfaces, including irregular textiles and smooth hard surfaces. The present invention also relates to a process for removing the aforementioned liquid wastes from the underlying surfaces. The powdered compositions include inorganic salt constituents in admixture with silica gel. However, unlike prior art inorganic salt compositions, the present formulations unexpectedly solidify into a coherent mass or cohesive solid matrix upon absorption of liquid waste, providing an easy and safe way to remove the debris.
As used herein, xe2x80x9ccohesivexe2x80x9d refers to sticking or adhering together tightly and firmly as part of the same mass. xe2x80x9cSolidxe2x80x9d refers to being uniformly close and having a coherent texture, wherein the material does not have an internal cavity. xe2x80x9cMatrixxe2x80x9d refers to a frame or mold. xe2x80x9cMassxe2x80x9d is a quantity or aggregate of matter.
The inorganic salts contained in the formulations of the present invention include, in part, an alkali metal sulfate, an alkali metal bicarbonate, and an alkaline earth metal sulfate. Generally, for removing both aqueous and oil-based spills, the alkali metal sulfate is included in the composition in an amount that ranges from about 5 parts by weight to about 85 parts by weight; the alkali metal bicarbonate in an amount that ranges from about 1 part by weight to about 75 parts by weight; and the alkaline earth metal sulfate in an amount that ranges from about 1 part by weight to about 70 parts by weight of the total powdered compositions. Preferably, the alkali metal sulfate ranges from about 20 parts by weight to about 85 parts by weight; the alkali metal bicarbonate from about 1 part by weight to about 25 parts by weight; and the alkaline earth metal sulfate from about 1 part by weight to about 45 parts by weight, based on the total weight of the novel powdered compositions.
Also, in the novel compositions, the alkali metal is preferably sodium and the alkaline earth metal is preferably calcium. However, the invention is not limited to the use of sodium sulfate, sodium bicarbonate, and calcium sulfate, and other alkali metal sulfates, alkali metal bicarbonates, and alkaline earth metal sulfates may be used, as would be apparent to those of skill in the art. Furthermore, the alkali metal sulfates, alkali metal bicarbonates, and alkaline earth metal sulfates useful in the present compositions are all inorganic salts, which, per se, are known in the art, and which are commercially available from a variety of sources.
Another ingredient, which must be included in the novel compositions, is silica gel, i.e. amorphous silica, which is available from a variety of commercial sources. The absorbent and dehydrating properties of the material make it an essential constituent of the present compositions. Inclusion of the silica gel is also critical for solidification to occur.
The silica gel constituent is present in the powdered formulations in an amount that ranges from about 1 part by weight to about 45 parts by weight, preferably from about 5 parts by weight to about 45 parts by weight, based on the total weight of the composition. When the amount of silica gel is above or below these specific range limits, no clumping or solidification is observed. For use in oil-based spills or stains, the preferred amount of silica gel in the composition is from about 20 parts by weight to about 35 parts by weight.
Surprisingly, other known desiccants and absorbents, such as zeolites, which are hydrated silicates of aluminum and either calcium or sodium or both, cannot be substituted for silica gel in the present compositions. Unexpectedly also, other forms of silica, such as silica powder cannot be used instead of silica gel. When such a substitution is made, the resulting mixture does not perform as a solidifying agent (sodification rating of xe2x80x9c0xe2x80x9d, as defined below), and only limited absorption is observed. This is very surprising because Coluriciello et al. (U.S. Pat. No. 5,738,494) cited above teaches that zeolites, both natural and synthetic, are interchangeable with silica gel for use as absorbents in carpet cleaning.
Commercially available, industrial grade materials may be used for each of the above-listed components included in the present powdered formulations. In addition, to ensure that the final compositions, after blending, are uniform and homogeneous, similar mesh sizes are generally used for each of the constituents. Dissimilar mesh sizes are generally undesirable, because they often result in separation of the ingredients. However, it is usually preferable, although not essential, to utilize crystalline metal bicarbonate, which has a larger mesh size than conventional powdered bicarbonate. The crystalline bicarbonate aids in the formation of a homogeneous mixture when blended with the other components. A suitable crystalline sodium bicarbonate formulation is commercially available from Natrium Products as sodium bicarbonate 5L.
The presence of all three inorganic salts in the specific limited ranges set forth above contributes to the overall effectiveness of the compositions in solidifying, cleaning, and absorbing the liquid wastes. As used herein, for a composition to be considered xe2x80x9ceffectivexe2x80x9d in removing liquid wastes, absorption of the liquid by the powdered composition must result in at least a moderate clumping having a rating of xe2x80x9c2xe2x80x9d based on a scale of 0-5, wherein xe2x80x9c0xe2x80x9d indicates no clumping or solidification; a rating of xe2x80x9c1xe2x80x9d represents slight clumping; xe2x80x9c2xe2x80x9d represents moderate clumping; xe2x80x9c3xe2x80x9d indicates slight solidification; xe2x80x9c4xe2x80x9d represents moderate solidification, and xe2x80x9c5xe2x80x9d indicates complete solidification.
For example, when all three inorganic salt ingredients were mixed with silica gel within the range amounts listed above, excellent absorption was observed, which resulted in complete solidification of the composition (5). Removal of the alkaline earth metal sulfate (calcium sulfate) resulted in moderate solidification (4). However, the use of only sodium sulfate (along with silica gel) absent sodium bicarbonate and calcium sulfate resulted in good absorption, but only moderate clumping (2). When individual components were tested, a solidification rating of only xe2x80x9c0xe2x80x9d or xe2x80x9c1xe2x80x9d was obtained, which does not facilitate the easy removal of the spill/composition from the underlying surface. Thus, performance (solidification) is optimal when all three inorganic salts are included with silica gel in the composition. Because water, containing nothing else, is the most difficult medium to solidify, water was used to test the effectiveness of the present compositions. The following example is illustrative.